import java.net.ServerSocket;


/**
 *
 */

public class test {
    String a = "test";
    public static void main (String args[]) {
        test t = new test();
        System.out.println(t.a);

        test a = t.changeout();
        System.out.println(a.a);
        
    }

    public test() { 
    }

    public test(test a) {
        this.a = a.a;
    }

    public test changeout() {

        // 这样创建的test是不会释放的
        test t = new test(this);
        t.a = "this is a's a";
        return t;
    }
}
